Aquaracer WAK2110 crown clarification

I recently bough an Aquaracer WAK21110 and when I screw in the crown I go till I feel the resistance and everythig is good. Well the issue is that after few minutes I could turn it again for like 30-45 degrees with little resistance until it stops. Then after some time the resistance goes away again and I can turn it a little bit. My question is, why is this happening and what is really going on on the inside of the screw-in mechanism?